Dealing with macOS Safari 11 "Stop Media with Sound" new feature

What is macOS Safari 11 "Stop Media with Sound" new feature?

End of September 2017, Apple publicly released Safari 11 as an update for macOS 10.12 users. Safari 11 will also be the default version of Safari for all macOS 10.13 users. With this new version Apple introduced a feature to limit "Auto-Play"
of media content on websites. By default all websites now have a "Stop Media with Sound" policy, which notably means that HTML5 video with an active audio track cannot autoplay anymore by default. Our testing shows that this applies to HTML5
video tag using the autoplay property or started programmatically with JavaScript without user interaction.

Accessing Safari 11 preferences a user can manage Auto-Play settings globally or individually for each visited website. Three settings are available:

Allow All Auto-Play: this is an opt-in option - HTML5 video autoplay is always available

Stop Media with Sound: this is the default - HTML5 video with active audio autoplay is not available but muted autoplay remains an option

Never Auto-Play: this is an opt-in option - HTML5 video autoplay is never available be it muted or not

Why this new feature?

Blocking autoplay of media content on websites has been a trend for the past few months in the industry. Many browser extensions and settings have come to see the light of day to allow fine tuning and blocking autoplay of media content. We can
put this in parallel with the other trend in the industry of blocking advertisement on websites through ad-blockers. The idea behind this trend is to provide users a better web experience when accessing media content, but one can imagine there
could be other aspects at stake.

This new Safari 11 feature is Apple way of embracing this trend and has received "quite a warm" welcome from the community. You can find an example of reaction on
reddit here.

So what do we do about it?

While we can imagine that some users are going to configure Safari 11 with the "Never Auto-Play" option we can also assume that most users will keep the default "Stop Media with Sound" setting. This means we can still use muted autoplay to start our media content for users that did not opt-in for the "Never Auto-Play" option.

Starting with Radiant Media Player version 4.4.19 we introduced the
mutedAutoplayOnMacosSafari11Plus setting which allow us to automatically opt for muted autoplay of HTML5 video specifically for macOS Safari 11. Older versions of Safari and other browsers will continue to autoplay with audio as
usual (where supported). This new setting allow muted autoplay of content and/or video advertisement on Safari 11+.

A note about using video advertisement with the Google IMA SDK on macOS Safari 11

As of September 22, 2017, starting a linear video advertisement (with audio) requires a separated (redundant) click for ads to render with the IMA SDK on macOS Safari 11. This is an implementation issue with the IMA SDK related to the "Stop Media
with Sound" new feature. This issue does not apply to muted autoplay of video ads with the IMA SDK on macOS Safari 11 which works as intended. We have already escalated this issue to the IMA team and are hoping for a fast solution. Alternatively
Radiant Media Player users may opt for our rmp-vast parser which is not affected by this new Safari 11 feature.